Preservation of oxidative metabolism in the face of ischemic insult is required for maintenance of myocardial viability and is a primary determinant of functional improvement following revascularization. Hyperinsulinemic euglycemic clamps will be done during FDG - PET scanning of myocardium to stabilize substrate entry into cells. In routine studies Beckman glucoses will be done during the study to detect and treat hyperglycemia.